diff options
Diffstat (limited to 'arch/alpha/include/asm/cmpxchg.h')
| -rw-r--r-- | arch/alpha/include/asm/cmpxchg.h | 20 |
1 files changed, 16 insertions, 4 deletions
diff --git a/arch/alpha/include/asm/cmpxchg.h b/arch/alpha/include/asm/cmpxchg.h index 8a2b331e43fe..6c7c39452471 100644 --- a/arch/alpha/include/asm/cmpxchg.h +++ b/arch/alpha/include/asm/cmpxchg.h @@ -38,19 +38,31 @@ #define ____cmpxchg(type, args...) __cmpxchg ##type(args) #include <asm/xchg.h> +/* + * The leading and the trailing memory barriers guarantee that these + * operations are fully ordered. + */ #define xchg(ptr, x) \ ({ \ + __typeof__(*(ptr)) __ret; \ __typeof__(*(ptr)) _x_ = (x); \ - (__typeof__(*(ptr))) __xchg((ptr), (unsigned long)_x_, \ - sizeof(*(ptr))); \ + smp_mb(); \ + __ret = (__typeof__(*(ptr))) \ + __xchg((ptr), (unsigned long)_x_, sizeof(*(ptr))); \ + smp_mb(); \ + __ret; \ }) #define cmpxchg(ptr, o, n) \ ({ \ + __typeof__(*(ptr)) __ret; \ __typeof__(*(ptr)) _o_ = (o); \ __typeof__(*(ptr)) _n_ = (n); \ - (__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_, \ - (unsigned long)_n_, sizeof(*(ptr)));\ + smp_mb(); \ + __ret = (__typeof__(*(ptr))) __cmpxchg((ptr), \ + (unsigned long)_o_, (unsigned long)_n_, sizeof(*(ptr)));\ + smp_mb(); \ + __ret; \ }) #define cmpxchg64(ptr, o, n) \ |